Amino acids bearing a norbornene moiety

Abstract

The invention relates to a novel amino acid having a norbornene group and polypeptide comprising the novel amino acid compounds. The invention also relates to a method of producing polypeptides comprising a norbornene group and to the use of said polypeptides.

The invention claimed is: 
     
       1. A compound having a norbornene group which has the following formula I: 
       
         
           
           
               
               
           
         
       
       wherein X is H or C 1 -C 6  alkyl, optionally substituted with a hydroxy, halogen, amine, thiol, or carboxy moiety, or wherein the compound is selected from the group consisting of D- or L-2-methylpyrrolidine-3-norbornene serine, D- or L-2-methyl(propyl)sulfane-3-norbornene serine, D- or L-2-1-butylguanidine-3-norbornene serine, L-2-propionamide-3-norbornene serine, and L-2-butyramide-3-norbornene serine. 
     
     
       2. The compound of  claim 1 , wherein the compound is selected from the group consisting of D- or L-3-norbornene serine, D- or L-2-methyl alcohol-3-norbornene serine, D- or L-2-methyl-3-norbornene serine, D- or L-2-isopropyl alcohol-3-norbornene serine, D- or L-2-methyl thiol-3-norbornene serine, D- or L-2-butane amine-3-norbornene serine, D- or L-2-isopentane-3-norbornene serine, D- or L-2-butyric acid-3-norbornene serine, D- or L-2-methylpyrrolidine-3-norbornene serine, D- or L-2-methyl(propyl)sulfane-3-norbornene serine, D- or L-2-1-butylguanidine-3-norbornene serine, L-2-propionamide-3-norbornene serine, and L-2-butyramide-3-norbornene serine. 
     
     
       3. The compound of  claim 1 , wherein the compound is selected from the group consisting of compounds having the following chemical structures: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
       4. A method for producing compounds of formula I, comprising the step of reacting norbornene-2-carboxaldehyde with an amino acid in the presence of threonine aldolase. 
     
     
       5. The method according to  claim 4 , wherein the amino acid is selected from the group consisting of glycine, alanine, serine, isoleucine, leucine, threonine, glutamic acid, proline, methionine, arginine, asparagine, glutamine, lysine and cysteine. 
     
     
       6. The method according to  claim 4  or  5 , wherein the threonine aldolase is of eukaryotic or prokaryotic origin. 
     
     
       7. The method of  claim 6 , wherein the threonine aldolase is of bacterial, yeast or fungal origin. 
     
     
       8. The method according to  claim 6 , wherein the threonine aldolase is from an organism in a genus selected from the group consisting of  Pseudomonas, Sphingomonas, Azorhizobium, Methylobacterium, Escherichia, Thermotoga, Silicibacter, Paracoccus, Bordetella, Colwellia , and  Saccharomyces.    
     
     
       9. The method according to  claim 8 , wherein the threonine aldolase is from  Pseudomonas putida.    
     
     
       10. The method according to  claim 4 , wherein the threonine aldolase is present in a cell lysate. 
     
     
       11. A polypeptide having a norbornene group which has the following formula II, 
       
         
           
           
               
               
           
         
         wherein: 
         X is H or C 1 -C 6 alkyl, optionally substituted with a hydroxy, halogen, amine, thiol, or carboxy moiety, 
         R 1  is OH, an amino acid, or a polypeptide moiety, 
         R 2  is H, an amino acid, or a polypeptide moiety, and 
         at least one of R 1  and R 2  is an amino acid or a polypeptide moiety. 
       
     
     
       12. The polypeptide of  claim 11 , wherein the norbornene group is incorporated into the polypeptide at a position corresponding to the position of the corresponding amino acid residue lacking a norbornene group in a wild type form of the polypeptide. 
     
     
       13. The polypeptide of  claim 11 , wherein said norbornene group is linked to a tetrazine group. 
     
     
       14. A method of producing a polypeptide comprising a norbornene group, comprising providing a polypeptide which comprises the compound of  claim 1 , contacting said polypeptide with a tetrazine or azide compound, and incubating the polypeptide and the tetrazine or azide compound to allow linkage of the tetrazine or azide to the norbornene group via cycloaddition reaction.